I"m sorry Gracie is in kidney failure. Unfortunately this is what happen to most cats as they age. I don't have any medical advice but I can tell you my experience that I had with Luigi my 17 yr old siamese cat that just went to the bridge. For the last seven years of his life he had been in kidney failure. He was dx when he was 10. The vets tried to get me to put him on their "special diet" of wet food, he hated it. Then they put him on the dry food "special diet". IT is very hard to get a cat to eat wet food after they have been raised on dry food. You have to be patient. Then I did some research and realized (for me) that quality of protien was better than quantity (they suggested low protien). I changed him to a good quality kibble and a good quality canned food. I put them in two different bowls and let him eat what he wanted. Sometimes he ate dry, sometimes he ate wet. I figured as long as he was eating that was the important thing. He also drank a huge amount of water. He lived for another 7 years this way.
I don't know if this method is along your lines of thinking, but it gave me 7 more years with my baby. They were good years and I cherished every one.
"Believe the Magic"
Lucy (Boxer), Indy & Henry (Bostons)
Jack & Avery, Chelsea & Frazier crazy buncha boxers waiting at the Bridge